Electric motors such as, for example, single phase induction motors are manufactured in a variety of configurations and are used in a number of different applications. For example, swimming pools and whirlpool spas typically use a number of electric motors for various purposes such as, for example, driving a water pump for water circulation purposes. Moisture, dust, and other contaminates, which typically are prevalent in the environments associated with these types of applications, interfere with the operation of the motor and, over time, may lead to failure of the motor. To provide protection against the adverse effects posed by these contaminants, various techniques and motor designs have been utilized.
One approach to combat the contaminant problem is to utilize a two-compartment motor. In a two-compartment motor, the stator, armature, and other primary motor components are contained in a first compartment and the secondary electrical components are contained in a second compartment. For example, U.S. Pat. No. 4,593,163 discloses a two compartment motor in which a starting capacitor, a thermal protector, a terminal board, a starting switch assembly, and a manually actuable switch are mounted to an end shield of an induction motor. A thermoplastic molded cover is secured to the motor with axially directed screws to define the second compartment of the motor.
U.S. Pat. No. 5,245,237 discloses another two-compartment motor in which a control assembly is mounted within a second compartment of a two-compartment motor. The control assembly includes a control plate, a plurality of electrical components, and mounting means for securing the electrical components in position on the control plate. In order to switch the voltage setting of the motor between high and low settings, a voltage selection switch is mounted on the control plate within the secondary compartment.
Constructing a two-compartment electric motor that is to be used, for example, in swimming pool and whirlpool spa applications as discussed above has a number of disadvantages. For example, the costs of manufacturing a two-compartment motor is higher than the cost of manufacturing a one-compartment motor due, for example, to the costs associated with the second compartment. Second, a two-compartment motor design does not include sufficient measures to protect the front-end bearings from the adverse effects of water-based corrosion which is a main cause of motor failure in the above-referenced applications. Third, mounting the voltage selection switch on a separate control plate in a second compartment as disclosed in U.S. Pat. No. 5,245,237 instead of directly on the motor frame unnecessarily increases the costs of manufacturing the motor.